Right, above we have the reflex unit disc.
The two single wipers pointing off to the left are
connected together on the hub, so as the wipers
reset (rotate counterclockwise) the wipers connect
rivets on the inner ring to rivets on the center
ring - effectively connecting solder lugs a
and b together.

On big time, nothing is connected to the a/b lugs, so
we can promptly forget all about them. That leaves us
with the six finger span of wipers labelled c.
The c wipers are connected to the wire marked c (yeah, it
looks like the c wire connects to the solder lug at the
edge, but it doesn't...it goes under the disc and connects
to another finger that pokes up and
touches the bottom of the c wipers. You'll see it in a later page).

big time

reflex schematic

Referring back to the schematic, we see that the schem shows
four wires connecting into the left side of the reflex unit box, and
one wire coming out the right side. The picture shows four wires
connected to the solder lugs, and one wire going under the disc to
the c wipers. Now we just need to figure out what the wires are doing.

About mixer #1

As mentioned, mixer #1
(diagram)
has a rotor with a single wiper that can connect green wire #21-3 to one of
24 rivets around the wiper board. The rivets are connected to the blue and
purple wires like this:

lug #

wire #

# rivets

odds

3

#56-4

3

12.50%

4

#54-4

3

12.50%

5

#53-4

3

12.50%

6 and 7

#75-5

12

50%

What's that mean? Well, half the time, mixer #1 stops
on a rivet that connects green wire #21-3 to purple wire
#75-5 directly, so the position of the reflex unit doesn't
matter.

The depending on the position of the reflex unit, mixer #1
will connect green to purple via the blue wires
12.5%, 25%, or 37.5% of the time.

If the reflex unit is reset far enough, it connects the
green to purple by itself and it doesn't matter where mixer #1
stops.

Note that the blue wires add in more chances of passing the
50V from green to purple, so the final odds of getting the
50V on the purple wire, depending on
the position of the reflex unit, is: